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New early Jurassic tetrapod assemblages constrain Triassic-Jurassic tetrapod extinction event.
Science. 1987 Aug 28; 237(4818):1025-9.Sci

Abstract

The discovery of the first definitively correlated earliest Jurassic (200 million years before present) tetrapod assemblage (Fundy basin, Newark Supergroup, Nova Scotia) allows reevaluation of the duration of the Triassic-Jurassic tetrapod extinction event. Present are tritheledont and mammal-like reptiles, prosauropod, theropod, and ornithischian dinosaurs, protosuchian and sphenosuchian crocodylomorphs, sphenodontids, and hybodont, semionotid, and palaeonisciform fishes. All of the families are known from Late Triassic and Jurassic strata from elsewhere; however, pollen and spore, radiometric, and geochemical correlation indicate an early Hettangian age for these assemblages. Because all "typical Triassic" forms are absent from these assemblages, most Triassic-Jurassic tetrapod extinctions occurred before this time and without the introduction of new families. As was previously suggested by studies of marine invertebrates, this pattern is consistent with a global extinction event at the Triassic-Jurassic boundary. The Manicouagan impact structure of Quebec provides dates broadly compatible with the Triassic-Jurassic boundary and, following the impact theory of mass extinctions, may be implicated in the cause.

Authors

No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

3616622

Citation

Olsen, P E., et al. "New Early Jurassic Tetrapod Assemblages Constrain Triassic-Jurassic Tetrapod Extinction Event." Science (New York, N.Y.), vol. 237, no. 4818, 1987, pp. 1025-9.
Olsen PE, Shubin NH, Anders MH. New early Jurassic tetrapod assemblages constrain Triassic-Jurassic tetrapod extinction event. Science. 1987;237(4818):1025-9.
Olsen, P. E., Shubin, N. H., & Anders, M. H. (1987). New early Jurassic tetrapod assemblages constrain Triassic-Jurassic tetrapod extinction event. Science (New York, N.Y.), 237(4818), 1025-9.
Olsen PE, Shubin NH, Anders MH. New Early Jurassic Tetrapod Assemblages Constrain Triassic-Jurassic Tetrapod Extinction Event. Science. 1987 Aug 28;237(4818):1025-9. PubMed PMID: 3616622.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - New early Jurassic tetrapod assemblages constrain Triassic-Jurassic tetrapod extinction event. AU - Olsen,P E, AU - Shubin,N H, AU - Anders,M H, PY - 1987/8/28/pubmed PY - 1987/8/28/medline PY - 1987/8/28/entrez SP - 1025 EP - 9 JF - Science (New York, N.Y.) JO - Science VL - 237 IS - 4818 N2 - The discovery of the first definitively correlated earliest Jurassic (200 million years before present) tetrapod assemblage (Fundy basin, Newark Supergroup, Nova Scotia) allows reevaluation of the duration of the Triassic-Jurassic tetrapod extinction event. Present are tritheledont and mammal-like reptiles, prosauropod, theropod, and ornithischian dinosaurs, protosuchian and sphenosuchian crocodylomorphs, sphenodontids, and hybodont, semionotid, and palaeonisciform fishes. All of the families are known from Late Triassic and Jurassic strata from elsewhere; however, pollen and spore, radiometric, and geochemical correlation indicate an early Hettangian age for these assemblages. Because all "typical Triassic" forms are absent from these assemblages, most Triassic-Jurassic tetrapod extinctions occurred before this time and without the introduction of new families. As was previously suggested by studies of marine invertebrates, this pattern is consistent with a global extinction event at the Triassic-Jurassic boundary. The Manicouagan impact structure of Quebec provides dates broadly compatible with the Triassic-Jurassic boundary and, following the impact theory of mass extinctions, may be implicated in the cause. SN - 0036-8075 UR - https://www.unboundmedicine.com/medline/citation/3616622/New_early_Jurassic_tetrapod_assemblages_constrain_Triassic_Jurassic_tetrapod_extinction_event_ L2 - https://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=3616622 DB - PRIME DP - Unbound Medicine ER -